The offline messaging feature is available for all QuickBlox SDKs.
You can find more information about the implementation of offline messaging for each of our SDKs at the links below:
Android SDK - Offline messaging | Chat | Android SDK | QuickBlox
React Native SDK - Offline messaging | Chat | React Native SDK | QuickBlox
Flutter SDK - Offline messaging | Chat | Flutter SDK | QuickBlox
Feel free to check our official documentation for more information that will help you to integrate QuickBlox services into your applications / projects or contact our Support team by submitting a ticket if you have any other questions.